There has been conventionally known a storage system for providing a plurality of clients (or tenants) with a storage apparatus including a plurality of resources. A data center operating the storage system concludes with the client a service level agreement (SLA) defining conditions for providing services, thereby guaranteeing the performance or the like of the provided resource.
In the above-mentioned storage system, in a case where a resource is to be allocated to a new client, when there is no available resource that satisfies the above-mentioned SLA, a resource that satisfies the SLA is secured by migrating data for other clients.
As examples of the technology of migrating data in providing a plurality of clients with resources in a computer system including the storage system, Japanese Patent Application Laid-open Nos. 2011-90594 A [PTL 1], 2008-176627 A [PTL 2], and 07-141270 A [PTL 3] are known.
Japanese Patent Application Laid-open No. 2011-90594 A discloses the technology for lowering the migration cost during scale-in/scale-out or workload consolidation of the cluster system to thereby reduce power consumption. Japanese Patent Application Laid-open No. 2008-176627 A discloses the technology with which migration is carried out to the access destination of the host apparatus without stopping data access between the host computer and the storage apparatus, and while continuing the functions of the storage apparatus. Japanese Patent Application Laid-open No. 07-141270 A discloses the computer system for creating a data transfer plan based on the time when the transmitted data is required, the amount of data, and the line speed so that the transmitted data is received by the time when the data is required on the reception side, and transferring the data.